1. Field of the Invention
The present invention relates to a power module of a field emission display and the method of power generation of the power module, and more particularly, to a power module of a field emission display and the method of power generation of the power module in which the field emission display is in a diode structure.
2. Description of the Prior Art
The surge of field emission display (FED) makes the planarization of cathode-ray tube (CRT) possible. The way the field emission display operates is similar to that of conventional cathode-ray tube, both of which emit electrons through a vacuum space, after which anodes accelerate these electrons to stimulate the phosphors so as to generate light. The phosphors for both FEDs and CRTs have the same characteristic. The major difference therebetween lies in the way electrons are generated, where a CRT generates electrons by heating the cathode while FED employs an electric field to attract electrons from the cathode.
Reference is made to FIG. 1, a cross-sectional view of a power source and a device of conventional diode FED with a micro acute end in metal. The conventional diode FED 1 with a micro acute end in metal has a stable DC power source 19 as a driving power, which connects to the anode layer 10 and cathode layer 14 of FED. When the DC power source is on, the emission layer 16 connected to the cathode layer 14 generates electrons and the DC power source 19 accelerates electrons to destroy the phosphors layer 12 coated on the anode layer 10, thereby stimulating phosphors units of the phosphors layer 12 to generate light. Additionally, an insulating layer 18 is placed for blocking electrons generated between each emission layer 16 to avoid mutual interference of these electrons. The emission layer 16 is a micro acute end in metal.
Reference is made to FIG. 2, a cross-sectional view of a power source and device of a conventional diode carbon nano-tube field emission display. The conventional diode carbon nano-tube FED 2 differs from the conventional diode FED 1 in having a micro acute end in metal with the field emission layer 16. In other words, the field emission layer in FED 1 in FIG. 1 is in metal while the field emission layer of FED 2 is composed of a carbon nano-tube.
Regardless of the characteristic of the field emission layers of above two field emission displays, both take advantage of DC power source 19 for the purpose of light generation. There are active and passive ways of driving field emission displays, in which the active method is adopted in thin-film manufacturing process having disadvantages of the use of comparatively more expensive manufacturing devices, complicated steps of manufacturing process and yield rate when applicable to medium or large-size panel manufacturing. On the other hand, the passive driving method provides a positive voltage differential impulse circuit with the disadvantage of inferior brightness performance, or a DC voltage differential circuit to the anode and cathode layers of the diode structure with the disadvantage of a shorter lifetime duration due to the continuing low voltage/high current situation leading to overheating of the panel device and circuitry.
Additionally, the required driving voltages between anodes and cathodes of conventional field emission displays are greater than 200 volts, resulting in the use of more expensive and complicated driving integrated circuits.